// 弹性布局 通用样式
.flex {
  display: flex;
  display: -webkit-flex;
  flex-direction: row;
  flex-wrap: nowrap;
  justify-content: flex-start;
  align-items: flex-start;
  &.is-wrap {
    flex-wrap: wrap;
  }
  &.is-center {
    justify-content: center;
  }
  &.is-space-between {
    justify-content: space-between;
  }
  &.is-space-around {
    justify-content: space-around;
  }
  &.is-mid {
    align-items: center;
  }
  &.is-btm {
    align-items: bottom;
  }
}
.pr {
  position: relative;
}
.pa {
  position: absolute;
}